This photograph shows the New Hampshire side of the Piscataqua River Bridge, also known as the Interstate 95 Bridge. (Photo courtesy NH.gov)

PORTSMOUTH — State police were forced to close down parts of Interstate 95 overnight because of icy conditions on the Piscataqua River Bridge connecting New Hampshire and Maine, and because of a fuel spill further south in Portsmouth.

Police said a tractor-trailer truck and several cars were unable to cross the Interstate 95 bridge when the surface of the road froze around 1 a.m. They were forced to stop, blocking the bridge.

Police closed the northbound travel lane for about an hour to allow crews to treat the road, according an announcement from State Police Sergeant Keith Walker. The road briefly reopened at 1:51 a.m., but was closed for another 10 minutes to allow for additional treatment. Workers from the New Hampshire and Maine departments of transportation assisted at the scene.

State police were then dispatched further south when a truck slid off the road near Exit 5 in Portsmouth. The cause of the crash is still under investigation. Police say the driver was heading south when he lost control around 2:18 a.m. His 2008 Peterbilt truck slid off the right shoulder of the road, broke through a guardrail and overturned.

The driver, 35-year-old Johnson Corrielus of Milton, Mass., was not injured. Police said approximately 50 gallons to 55 gallons of diesel fuel spilled onto the ground after one of the fuel tanks was punctured. The right breakdown lane and right travel lane of Interstate 95 south remained closed for several hours while crews were cleaning up the fuel spill.

Personnel from the Portsmouth Fire Department and the state departments of transportation and environmental services assisted at the scene. Officials from the New Hampshire State Police Commercial Vehicle Enforcement Unit also took part in the response.

State Police Trooper Kevin Devlin is investigating the truck crash. Anyone with information about the accident is asked to contact him at 603-223-8490.